Well, Windows 7 is going to be released by the end of next year. This is great news, because it seemed, that Microsoft finally understand how to get the best of Windows Vista and make it to work not only on monster machines.

Windows Driver Kit (WDK) 3.0

Basically, Windows 7 works with Vista drivers, however, hibernation, power management, networking, PREfast will work much better. You also will have new WMI access for reliability monitors and ACPI.
Management and deployment

By default Windows 7 uses PowerShell 2.0 and Windows Installer. For PowerShell it includes enhanced cmdlets to manage Active Directory, IIS, etc. For Windows Installer, you finally can build "chainers" by yourself (the same approach, used for latest deployment of Microsoft products such as Silverlight, Visual Studio 2008 SP1 etc.) Also, you can get advantage by using Windows Filtering Platform (Firewall) and User Account Control (UAC) from inside your application by using new APIs.